Why helium exist in the form of he not he2?

Answer 1

he2 is a fatty. He atom is a inert gas. so it can not react with any other atom or molecules to form any compounds.so He2 can't exist.

ANOTHER ANSWER: Helium atom has only one shell i-e K-shell which can accommodate a maximum of two electrons which it already has. therefore Helium atom does not need any more electrons to become stable as it is already stable by duplet rule. Thus helium atom does not combine with another helium atom and hence exists as He and not He2.

Answer 2

Hydrogen has one outer electron. But two electrons are needed to be stable, therefore Hydrogen atoms join together to become stable. Since heliums are already stable they do not need to bond together.

Answer 3

A hydrogen atom is more likely to react with other atoms than a helium atom because of its unfilled s-orbital. The 1s orbital has a maximum capacity of two electrons, at which point it cannot have any more. When in this state, it is relatively unreactive. A helium atom is already in this state (it is a noble gas).

A hydrogen atom only has one electron in its 1s orbital, which allows it to react readily with many different types of atoms. This will often (but not always) cause the hydrogen atom to either lose its electron through an ionic bond or have a full 1s orbital through the sharing of electrons. Either of these options lower the potential energy of the system, making it more stable.

Answer 4

hydrogen has one electron in its 1s orbital it can combine with another H atom to form H2 and "achieve" a noble gas configuration, in this case that of helium.

Helium on the other hand already has a filled 1s orbital (2 electrons) and therefore does not combine with another He atom.